This invention relates in general to vehicle wheels and in particular to wheels having a separately formed wheel rim attached to a cast full face wheel disk.
It is known in the art to fabricate a vehicle wheel by attaching a rolled steel wheel rim to a wheel disk cast from a light weight metal, such as aluminum, titanium or magnesium or an alloy thereof. Such a wheel is referred to as a bimetal wheel and combines the economy, flexibility and strength of a steel rim with the pleasing ornamental appearance of three dimensional contours formed in a cast wheel disk.
To further enhance the appearance of a bimetal wheel, it is known to radially extend the wheel disk to include the outer tire bead retaining flange. Such a wheel disk is referred to as a full face wheel disk. The full face wheel disk is attached to a truncated end of a partial wheel rim having only an inner tire bead retaining flange. The assembled full face wheel disk and partial wheel rim is called a full face wheel. When a tire is mounted upon a full face wheel, the joint between the wheel rim and the wheel disk is completely hidden.
Referring to FIG. 1, there is shown, generally at 10, a sectional view of a typical prior art bimetal full face wheel. The wheel 10 includes a full face wheel disk 11 cast from a light metal or alloy. The wheel disk 11 has a ring shaped rim 12 which includes an outboard bead seat flange 13. The flange 13 has an inboard surface 14 that faces a vehicle (not shown) when the wheel 10 is mounted thereon. The wheel disk 11 also includes a ring-shaped weld anchor 15 formed from a ferrous material, such as steel. The weld anchor 15 is partially embedded in the flange inboard surface 14. As best seen in the fragmentary sectional view of the wheel 10 shown in FIG. 2, a portion of the weld anchor 15 is exposed to form a welding surface 16. An inboard annular-shaped portion 17 of the wheel disk 11 overlaps a portion of the weld anchor 15, forming a cylindrical shoulder 18 extending perpendicularly away from the weld anchor 15.
A conventional drop-center partial wheel rim 20 is attached to the wheel disk 11. The wheel rim 20 can be formed from steel strip stock with conventional rim roll forming machinery. The wheel rim 20 includes a conventional inboard bead seat flange 21 and a cylindrically-shaped outboard end 22. The outboard rim end 22 extends axially over the shoulder 18 formed on the annular portion 17 of the wheel disk 12. The outboard rim end 22 and the wheel disk annular portion 17 are sized to form a clearance fit therebetween, allowing the wheel rim 20 to be rotated relative to the wheel disk 11.
The wheel rim 20 is attached to the weld anchor 15 by a continuous air-tight weld 25 formed between the weld anchor 15 and the wheel outboard rim end 22. The weld 25 is typically formed by a conventional friction or inertial welding process wherein the wheel disk 11 is held stationary while the outboard rim end 22 is rotated against the weld anchor 15. During the welding process, the weld 25 is formed having a weld radius 26 for seating a tire bead. Accordingly, the weld radius 26 generally matches the radius formed on the inboard bead seat flange 21.